The present invention relates to an electronic apparatus for counting railway axles and cars irrespective of their type, speed or running direction.
Car counters are known which are of an electromechanical construction and which are used in marshalling yards for transducers, these counters use two electromagnetic treadles placed at a certain distance. The drawback of this type of counters is that as it offers no opportunity for discrimination, since it can be used for counting only one car type.
A car counting discriminator is disclosed in Romanian patent 58714, that makes use of two treadles that control a logical network built of relays. Although this type of counter permits the counting of several car types, it still has certain drawbacks such as: it has a low reliability; it operates only for cars traveling at up to a 30 km/h speed; for cars discrimination it necessitates that the axles should be symmetrically placed as against the transverse median; it cannot discriminate cars whose distance between the bogies axles is greater than 2200 mm; and it cannot dscriminate cars with more than 8 axles.
The detecting system disclosed in U.S. Pat. No. 1,339,971 stipulates conditions for discriminating only cars with four or six axles. The system consists of two treadles and it can be enlarged to four treadles as well.
The system does not specify the distance between treadles and does not refer to cars with two axles or with more than six axles, and the electronic circuitry used is very complex. The fact that the distance betwen treadles is not specified makes the discrimination of many car types debatable.
Another system for detecting a vehicle presence, is disclosed in U.S. Pat. No. 3,500,039. The vehicle detection is made by comparing the states of two counters that can detect the passage of a bogie, which can have at most three axles. This procedure implies the existence of symmetry of the front-back axles number. The system does not specify the distance between treadles, and this makes the discrimination of some car types debatable. This system also does not discriminate cars having more than three axles on a bogie or vehicles whose number of front-back axles is not equal, and moreover the circuitry used is very complex.
There is also known the method and the apparatus described in U.S. Pat. No. 3,646,327. The circuit thereof uses four electronic treadles placed in the track at determined distances. The circuit operation is described for the discrimination of standard American vehicles with 4, 6 and 8 axles. The apparatus does hot detect two axle cars; cars with more than four axles per bogie, or cars that do not have the same number of front-back axles. Additionally, the circuitry is complex and uses a great number of treadles.
Another known method and apparatus is disclosed in U.S. Pat. No. 3,745,335. The system uses for discrimination, two treadles placed at minimum 3850 mm and at maximum 3352 mm one against the other. Each treadle operates a counter and the counters are subject to reset conditions after the passage of each vehicle. The counter states are reciprocally compared as against certain unique states. This system applies to the discrimination of standard American railway vehicles with 4, 6 and 8 axles only. The system does not refer to two axles cars. It often happens that the distance between the axles of two coupled cars should be smaller than 3150 mm. These car types will not be discriminated. The system does not refer to cars having more than 4 axles per bogie and cannot detect cars having unequal number of front-back axles.